1. Field of the Invention
Apparatuses and methods consistent with the present invention relate to generating frequencies, and more particularly, to generating center frequencies for use in multi-band hopping communication.
2. Description of the Related Art
A frequency generator is used to generate frequencies required for modulation/demodulation and supply the generated frequencies to a modulator/demodulator. In multi-band hopping communication, such a frequency generator generates center frequencies of bands.
A frequency generator generates frequencies required for modulation/demodulation by multiplying an oscillation frequency generated by an oscillator. An oscillation frequency generated by the oscillator generally includes a frequency offset. As a result, a frequency generated by the frequency generator also includes a frequency offset. This is because a frequency generator generates frequencies required for modulation/demodulation using an oscillation frequency generated by an oscillator.
Such a frequency offset deteriorates modulation/demodulation property, and particularly, the deterioration of modulation/demodulation property is a more serious problem in ultra wide multi-band hopping communication.
Therefore, frequency offsets need to be corrected, and accordingly, a method for correcting frequency offsets should be developed.
Conventionally, frequency offset correction has been mainly performed in base band. For this reason, although the conventional frequency offset correction is suitable for use in low-speed communication, it is not suitable for use in high-speed communication such as ultra wide multi-band hopping communication.
Also, the conventional frequency offset correction has generally been performed using a phase locked loop (PLL). However, the conventional frequency offset correction using the PLL is unsuitable for use in ultra wide multi-band hopping communication with a very short band transit time (approximately 9.5 ns).
Therefore, a method for correcting frequency offsets in ultra wide multi-band hopping communication is nowadays needed.